Multiple four-way control valve

ABSTRACT

A multiple four-way control valve having a spool within a cylindrical bore defined in the valve housing with first and second pressure grooves defined around the cylindrical bore communicating with first and second pressure channels defined within the valve housing with an outlet port communicating into the cylindrical bore. An inlet port communicates with the cylindrical bore through a first and second relief channel which relief channels further communicate to first and second relief grooves. A first second, third and fourth slots are defined on the spool members adapted to align at various positions to elements of a first and second series of operation ports.

This application is a continuation-in-part of my previously filedapplication, Ser. No. 215,272 filed Dec. 11, 1980 of the same title, nowU.S. Pat. No. 4,337,796 issued July 6, 1982.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to valves and more particularly to rotary spoolvalves.

2. Description of the Prior Art

Spool valves for utilization with hydraulic control systems includingthe use of four-way valves are well-known in the prior art. The inventorof the present invention has received five prior U.S. Patents in thisarea, namely U.S. Pat. No. 3,774,504 for a Sliding Spool Valve; No.4,027,697 for a Rotary Valve; No. 4,124,038 for a Multiway HydraulicValve; No. 4,184,513 for a Multiple Three and/or Two-way Valve; and No.4,177,834 for a Rotary Four-way Tandem Center Valve. These patents andthe references cited therein are related to the field wherein thepresent invention resides. Also considered relevant in the prior art areU.S. Pat. No. 3,213,881 to J. B. Findlay et al for a Directional ControlValve and U.S. Pat. No. 2,749,941 to L. E. Gardiner for a Rotary ControlValve.

SUMMARY OF THE INVENTION

The present invention is a multiple four-way control valve with a tandemcenter spool having a uniform flow rate regardless of the number ofunits in the system and which is adapted so that other valves can bealigned therewith.

It is an object of this invention to provide such multiple four-waytandem center directional control valve for the control of double-actinghydraulic cylinders, reversible hydraulic motors and the like.

It is a further object of this invention to provide a valve of simpleand economic construction which does not necessarily utilize checkmember. The valve of this invention can take the place of a plurality ofvalves making it cheaper to use, lighter in weight, and more compact.

It is a still further object of this invention for one control tooperate all of the functions controlled by the valve. The instantinvention can be adapted to vary the speed of each or more than one ofthe cylinders or elements controlled which speed can be increased forone portion and decreased at another portion of the system at the sametime.

It is yet a still further object of this invention to provide aflowthrough design for pressure beyond the valve.

The present invention comprises a valve housing having a cylindricalbore defined therein. An inlet port is defined within the valve housingso that a first and a second pressure channel also defined within thevalve housing communicate with the inlet port and the cylindrical boreto allow the entrance of hydraulic fluid into the cylindrical bore fromthe inlet port. First and second pressure grooves are defined around thecylindrical bore of the valve housing communicating with the firstpressure channel and the second pressure channel, respectively. Anoutlet port is also defined within the valve housing communicating intothe cylindrical bore. First and second relief channels are defined inthe valve housing extending from the sides of the inlet port through thevalve housing to first and second relief grooves defined respectivelywithin the cylindrical bore. The spool member is rotatably, axially andmovably positioned in the cylindrical bore with a central spoolprojection member extending therearound adapted so that its outerperiphery contacts the valve housing surrounding the cylindrical bore. Afirst series of four slots are defined upon the rotary spool member inaxial alignment and a second corresponding set of four slots are definedon the opposite side of the spool member, the first and fourth slots ofthe first set are aligned and communicate with the first and secondrelief grooves respectively when the rotary spool is in a neutralposition while the second and third slots of the first series arealigned and communicate with the first and second pressure groovesrespectively which are adapted to empty into the outlet chamber. A firstand second series of operational ports are each arrayed in a transverseplane to the axis of the spool adapted to be aligned with the slotsdefined in the spool dependent on the position of the spool. Seal meansare provided adapted to seal the spool in a fluid-tight relation withinthe cylindrical bore. Also, means to equalize pressure opposite each ofthe operation ports, such as by balance cavities or by balance channelsopposite each operation port in the valve housing are provided.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates the valve body in horizontal cross-section with spoolin place.

FIG. 2 illustrates a cross-section of the valve body and spool invertical position with spool in operating position.

FIG. 3 illustrates a cross-section through either section A--A or B--Bof FIG. 2.

FIG. 4 shows an alternate embodiment of the valve housing with backpressure compensation means.

FIG. 5 illustrates closed center design of valve.

DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 illustrates a top view of a horizontal cross-section of thedevice of this invention having valve housing 10 with cylindrical bore14 defined therein. Valve housing 10 includes inlet port 16 and outletport 18. The inlet port divaricates into a first and second pressurechannel 26 and 28, respectively which enter into cylindrical bore 14 andextend therearound in the form of first pressure groove 27 and secondpressure groove 29. Outlet port 18 also extends into cylindrical bore 14and has portions emanating therefrom through valve housing 10 forming afirst relief channel 30 and a second relief channel 32 which extend toand around cylindrical bore 14 in the form of a first relief groove 34and second relief groove 36. Also aligned radially in a semi-circlearound the cylindrical bore are a first series of operation ports, oneof which 46 is seen in FIG. 2 and others, for example, 45 and 47 in thesame plane as 46 are seen in FIG. 3 which is a cross-section throughB--B seen in FIG. 2. These operation ports communicate into cylindricalbore 14 as does a second series of operation ports which are in a planeparallel to the first series as seen in FIG. 2 and which is depicted bysecond operation port 48 of which the second series has at least one ormore other operation ports not seen in that view but which arecomparable to the ones seen in FIG. 3. Within cylindrical bore 14 isrotary spool 12 which, at either end thereof, is of a diameter adaptedto contact the cylindrical bore in fluid-tight relationship. If desired,sealing means such as a first O-ring 20 and a second O-ring 22 can beutilized within grooves defined within the spool or in the valve housingto assist in forming such fluid-tight relationship between the spool andthe valve housing. The spool is rotatable within the valve housing andalso axially slidable. It can be retained therein by conventional meanssuch as by a lockring 24 which can be mounted within a groove of thesegment of the spool which can protrude out the valve housing or byequivalent conventional means. The spool can be manually rotated orrotated by other conventional means as desired and may include stopmembers to limit its rotational movement and detents for determinationby the user as to the rotated position of the spool within the valve.The spool can be self-centering in a neutral position by spring membersor other well-known conventional means. Positioned on a central portionof the spool within outlet chamber 44 while the spool is in a neutralposition is central spool projection 42 whose periphery is adapted tomake fluid-tight contact with the sides of the cylindrical bore. Definedalso on the outer peripheral surface of the spool are a first series offour axially extending slots 38, 40, 39 and 41, each of which slots asseen in FIG. 1 have corresponding slots defined on the opposite side ofthe spool as seen in FIG. 2 and numbered 38A, 39A, 40A and 41A. Whenthis first series of slots are aligned in a neutral position, slots 39and 39A and 40 and 40A allow the fluid from the inlet port to pass frominlet port 16 through first and second pressure channels 26 and 28,through first and second pressure grooves 27 and 29, around the rotaryspool wherein the fluid passes into slots 39 and 39A and 40 and 40A andwill then be directed to a narrow portion of the spool and into outletchamber 44 to pass out through outlet port 18. All operation ports inthe neutral position will be closed as a land of the spool will bealigned therewith so that they are in an inactive position. If the spoolis pushed to an active position, for example, as seen in FIG. 2 wherethe central spool projection is now aligned with land 101 of the valvehousing, and first operation port 46 is now pressurized through groove40 because of the fluid coming through first pressure groove 27 and atthe same time groove 38 is now aligned with one of the second operationports 48 and the fluid passes through second relief groove 36, aroundthe rotary spool, through second relief channel 32, into outlet chamber44, and out outlet port 18. If the rotary spool is rotated, slot 40would align first pressure groove 27 with either ports 45 and 47 as seenin FIG. 3 depending upon how the spool is rotated or the spool may berotated midway between the ports thereby pressurizing two of theoperation ports at the same time or pressurizing one of the operationports more than the other if the spool is only partially turned to openinto one of them. On the spool slot 38A is opposite slot 38 and isaligned with pressure balance cavity 50 so that the pressure will beevenly distributed on either side of the spool to allow for its easymovement so that it is not forced against a portion of the cylindricalbore. Such pressure balance cavities are located opposite each of theoperation ports.

The slots are formed on the first and second collar member 60 and 62 ofthe spool having a first, second, third and fourth cut-away sectiondefined at the ends of each collar 64, 65, 66 and 67 with the second andthird cut-away sections being on either side of the central spoolprojection. The slots have the same diameter as the operation ports andeach slots extends on the axis of the cylindrical bore toward thecut-away sections with their rear ends rising up to meet the cylindricalbore.

It should be obvious, if spool 14 is pulled in the opposite direction asdepicted in FIG. 2 so that central spool projection 42 aligns with land102, the reverse steps take place thereby relieving operation port 46and pressurizing operation port 48. In an alternative mode ofconstruction in case of high back pressure, opposite pressure balancecavities having a separate tubing member 54 seen in FIG. 4, being eithera tubing outside or a channel within the casing through which the fluidflows which may be utilized to equalize the pressure on either side ofthe spool.

The embodiment in FIG. 5 is of a closed center valve which eliminatesthe outlet from cylindrical bore 14 to outlet chamber 44 seen in thetandem center version in FIG. 1. This closed center version furtherfills in a land around cylindrical bore 14 and is useful on closedsystems and in other respects is the same as the tandem center versionin FIG. 1.

Although the present invention has been described with reference toparticular embodiments, it will be apparent to those skilled in the artthat variations and modifications can be substituted therefor withoutdeparting from the principles and spirit of the invention.

I claim:
 1. A multiple four-way control valve comprising:a valvehousing; a cylindrical bore defined within said valve housing; an inletbore defined within said valve housing; first and second pressurechannels defined within said valve housing communicating with said inletport and said cylindrical bore, to allow the entrance of hydraulic fluidinto said cylindrical bore; first and second pressure grooves definedaround said cylindrical bore of said valve housing communicating withsaid first and second pressure channels respectively; an outlet portdefined within said valve housing; first and second relief channelsdefined in said valve housing, extending from said inlet port throughsaid valve housing to said cylindrical bore; first and second reliefgrooves defined around the inside of said cylindrical bore in said valvehousing communicating with said first and second relief channels; afirst series of operation ports of like diameter defined in said valvehousing arrayed in a first transverse plane to the axis of, andcommunicating with, said cylindrical bore; a second series of operationports of like diameter defined in said valve housing arrayed in a secondtransverse plane to the axis of, and communicating with, saidcylindrical bore; a spool member positioned in said cylindrical bore andbeing rotatably and axially movable within said cylindrical bore; acentral spool projection member extending around and projecting fromsaid spool member with its outer periphery contacting said cylindricalbore; first and second collar members protruding from said spool memberand contacting said cylindrical bore, each spaced equidistant from saidcentral spool projection, the inner portions of said first and secondcollar members extending, when said spool member is in a neutralposition, to block said first and second pressure channels and saidfirst and second pressure grooves, and the outer portions of whichextend beyond said first and second relief grooves and said first andsecond relief channels, said first and second collar members defining afirst, second, third and fourth cutaway section around said spool attheir respective inner portion ends and outer portion ends, said secondand third cutaway sections being separated by said central spoolprojection; first and second slots defined upon said first collar memberand third and fourth slots defined on said second collar member, all inaxial alignment, said first slot aligned with said first relief groovewhen said rotary spool is in a neutral position, said second slotaligned with said first pressure groove to empty said first pressuregroove into said outlet chamber, said third slot positioned on saidvalve aligned with said second pressure groove to empty said secondpressure channel into said outlet chamber; and said fourth slot alignedwith said second relief groove; seal means adapted to seal said spool ina fluid-tight relation in said housing within said cylindrical bore; asecond series of slots defined on said collar members to equalizepressure on said spool opposite each of said operation ports, each slotopposite one of said first, second, third and fourth slots with aplurality of cavities defined in the valve housing opposite eachoperation port, said cavities aligned with said second series of slotson said spool; each of said slots in said first and second series ofslots having a width of the diameter of one of said operation ports withits inside rear end terminating at a point contacting said cylindricalbore and its outside end opening into its respective cut-away sectionaround said spool; and said spool when in said neutral position blocksall of said operation ports, said spool if moved into an active positioncloses off one of said pressure channels by a land on one of saidcollars while directing the pressure through said slot on the othercollar to a rotationally selected operation port while relievingpressure on a corresponding selected operation port of the other seriesby venting it through a slot on the other collar to said relief channeland to said outlet port.
 2. The valve of claim 1 wherein said outletport communicates into said cylindrical bore and said spool when in saidneutral position and under pressure allows hydraulic fluid to passthrough said first and second pressure channels around through saidfirst and second pressure grooves, through said narrower cut-away secondand third sections of said spool and out said outlet port while saidspool is blocking all of said operation ports, said spool if moved intoan active position where said central spool projection is aligned withand contacting said cylindrical bore, further closes off one of saidpressure channels by a land on one of said collars while directing thepressure through said slot on the other collar to a rotationallyselected operation port while relieving pressure on a correspondingselected operation port of the other series by venting it through a sloton the other collar to said relief channel and to said outlet port. 3.The valve of claim 1 or 2 further including means forming a channel foradditional relief of high back pressure extending from said cavityopposite each operation port into said operation port to allow fluidunder pressure to reach said cavity from said operation port.